Improvement in steam safety-valves



Qnitbtatrs atrnt @ffies- EDWARD H. ASHCROFT, OF LYNN, MASSACHUSETTS.

Letters Patent No. 82,270, dated September 22, 1868.

IMPROVEMENT IN STEAM SAFETY-VALVES.

ih .tlphnle referto: in in tiges tctters tant mit making part nf the same.

T0 ALL WIIOM IT MAY CONGEURN:

Be it known that I, EDWARD H. ASHCROFT, of the city of Lynn, county of Essex, in the State of Massa chusetts, have invented a new and useful Improvement in Steam Safety-Valves; andI do hereby declare the following is a full and exact description thereof, reference being had to the accompanying drawing, making a part of this specieation.

The nature of my invention consists in the construction of that part of my valve and its seat, more immediately exposed to the action of steam, of a metal less liable to be corroded by it.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction.

Thedrawing represents a section through a steam safety-valve of ordinary shape or structure, showing the several inlets and outlets for steam.

a a is the usual valve-seat or partition; b b, the valve, with its stem and lower guides.

The action of steam on valves of ordinary manufacture is well known, corroding the same to such extent as to cement them totheir seats, and enable them to resist many pounds more of steam than they are designed to blow o' at without being raised, thus endangering, perhaps, the safety of a boiler, and the lives of those employed about it. To avoid this, I make the seat proper of an anti or non-corrosive metal, and this can most easily and cheaply be done by screwing in the partition a ring of such metal or alloy,'seen at s s. I also secure to the stem, in any suitable manner, the valve proper, t t, made of au anti or non-eorrosive metal or alloy,

to be fitted to the seat below. These parts, being more immediately subjected to the actionrof` steam, moisture, Snc., are thus prepared to resist any deleterious action of the same, lessen or avoid wear, and insure safety, so far as adhesion is concerned.

The metal I propose using principally for the purpose named is an alloy of pure copper, nickel, and aluminium, in such proportions as will give the desired hardness Vfor wear; but I may use aluminium` alone, or alloys of gold or silver.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is I I The construction of the valve l, with its alloy t, with-reference to its seat s, us an article of manufacture,

substantially as herein set forth.

E. H. ASHCROFT.

AWitnesses:

J. P. l'J.111-:0D0RE LANG, C. FAHNEsTooK. 

